.\"	intro.4 -- 1.2 Sep 30 06:26:11 1993
.\"	Copyright (c) 1993 Axel T. Schreiner
.TH intro 4 "local: ats"
.SH NAME
intro \(em introduction to the calculator application
.SH SYNOPSIS
.nf
.ta 30n
Objct	Class
    Event
    Ic	    IcClass
        Button
        Calc
        Crt
            CButton
            CLineOut
        LineOut
        Mux
    List	    ListClass
    Xt
        XawBox
        XawCommand
            XButton
        XawForm
        XawLabel
            XLineOut
        XtApplicationShell
.fi
.SH DESCRIPTION
.BR Object (3)
is the root class.
.B Object
needs to be renamed as
.B Objct
because the original name is used by X11.
.PP
.BR Event (4)
is a class to represent input data such as key presses
or mouse clicks.
.PP
.BR Ic (4)
is the base class to represent objects that can receive,
process, and send events.
.B Button
converts incoming events to events with definite text values.
.B Calc
processes texts and sends a result on.
.B LineOut
displays an incoming text.
.B Mux
tries to send an incoming event to one of several objects.
.PP
.BR Crt (4)
is a class to work with the
.I curses
terminal screen function package.
It sends position events for a cursor
and text events for other key presses.
.B CButton
implements
.B Button
on a
.I curses
screen.
.B CLineOut
implements
.BR LineOut .
.PP
.B List
manages a list of objects and is taken from chapter 7.
.PP
.BR Xt (4)
is a class to work with the X Toolkit.
The subclasses wrap toolkit and Athena widgets.
.B XButton
implements a
.B Button
with a
.B Command
widget.
.B XLineOut
implements a
.B LineOut
with a
.B Label
widget.
.SH SEE ALSO
curses(3), X(1)
